Passenger entertainment systems are in widespread use in public-transport vehicles such as jet aircraft. These systems include audio equipment for reproducing recorded music or other program material, and the equipment may also be used in conjunction with visual programs presented on a film screen or television display in the passenger compartment of the vehicle.
To enable selective use of the entertainment system, individual earphones are provided to the passengers for plug-in connection to the audio output of the system. Conventional electromagnetic earphones can be used in this application, but acoustic-style headsets are generally preferred for economy, and for simplified cleaning and repackaging enabling re-use of the headset.
An acoustic headset does not include an electromagnetic transducer, and is instead a simple tubing system for conveying sound waves from speakers or similar transducers which are typically located in the passenger's seat. Separate sound tubes enable transmission of two-channel stereo program material, and the tubes terminate in a conventional connector which plugs into a mating receptacle in the passenger's seat.
Acoustic headsets have been used in airline service for many years, but known designs are not completely satisfactory for several reasons. Conventional units are somewhat uncomfortable to wear for long periods of time, and are acoustically inefficient in having poor frequency-response characteristics and improper orientation with respect to the ear canals of the user. These units also have sound-conducting tubes which are supported on the headset yoke in a way which produces sharp bends in the tubing when the headset is packaged. These bends cause kinks in the tubing which further impair the quality of sound transmitted to the user.
Our new design overcomes these problems, and provides an economical multiple-use headset of improved acoustic quality. The new headset uses sound tubing of enlarged diameter as compared to conventional styles, and the tubes terminate in internally tapered horns for further improvement in frequency response. The horns are rotatably mounted on a supporting yoke, and are otherwise configured to enable proper alignment with the typical inwardly downward and forward orientation of human ear canals. The sound tubes are free of mechanical connection to the headset other than at the input ends of the horns, thus permitting the tubing to be neatly coiled without kinks after the unit is cleaned and is ready for repackaging.